Connector assembly

Abstract: This invention provides a connector which prevents female and male terminals from coupling partially to each other upon coupling and detaching of female and male connectors. in the assembly, the male connector is provided with a guide rod (13) which projects in a coupling direction. The female connector is provided with a guide hold (20) through which the guide rod passes. Upon coupling of both connectors, the guide rod passes through the guide hole to position an insertion direction. The male terminal enters the female terminal without inclining and partially contacting.

Description: This invention relates to a connector assembly and more particularly to a connector assembly comprising a male connector and a female connector. For convenience of explanation, a conventional connector assembly will be described below by referring to FIG. 13. FIG. 13 is a longitudinal sectional view of the conventional connector assembly. In the conventional connector assembly, as shown in FIG. 13, a male housing 61 is provided on one side with a male hood 62 in which male terminals 63 project outwardly. On the other hand, female terminals 65 are attached in a mating female housing 64. When both housings 61 and 64 are coupled to each other, the male terminals 63 are fitted in the female terminals 65, respectively. Upon coupling of both housings 61 and 64, they are coupled to each other after they are completely opposed. Accordingly, even if they are being coupled to each other in an inclined posture, their relative insertion direction is gradually corrected by the male hood 62. However, when a distal end of the male terminal 63 reaches an inlet 66 of the female housing 64, the coupling directions of the male and female terminals 63 and 64 are not coincidental with each other and there a small angle α (FIG. 13) exists between the coupling directions. Consequently, the distal end of the male terminal 63 is inserted into the female terminal 65 while the distal end partially contacts with the insertion port 66 or a coupling aperture of the female terminal 65. The male terminal 63 may be bent by such partial contact. In the case where coupling and detaching of the male and female terminals under partial contacts are repeated or where coupling and detaching of the male terminal 63 under its partial contact due to its deflection are repeated, the distal end of the male terminal 63 is worn and this results in a failure of an electrical contact between the male and female terminals 63 and 65. In particular, in a connector with a gold-plating layer for enhancing reliability of contact, the gold-plating layer will become worn. In addition, manual work of fitting an end face of the female housing 64 to the male hood 62 tends to be carried out roughly. When the female housing 64 is forcibly fitted to the hood 62 while the housing 64 is inclined, the end face of the housing 64 pushes slantwise against an opening edge of the male hood 62 and they may be deformed or broken. We are also aware of European Patent Application No. EP-A-0 238 801 which discloses a male connector and a female connector with a guide rod provided on one of the connectors to engage with a guide means on the other one of the connectors so as to constrain the coupling direction of the connectors. This document has been used as the basis of the precharacterising portion of the claims. However, in practice this arrangement is disadvantageous in that the guide rod is concealed within the connectors after assembly and so it is not possible to readily note if a correct and full connection has been made. An object of the present invention is to provide a connector assembly which can prevent female and male terminals from being only partially coupled to each other. Another object of the present invention is to provide a connector assembly which can prevent an end face of a female housing and a male hood from being deformed or broken upon coupling of female and male housings. In order to achieve the above objects, we provide a connector assembly comprising a male connector having a projecting male terminal and a male hood around the male terminal coupled to a female connector having a female terminal to interconnect the male and female terminals, in which, a first one of said male and female connectors is provided with a guide rod projecting in a coupling direction and having a distal end remote from said first connector, and a second one of the connectors is provided with a guide hole for introducing the guide rod and a rear face at the end of said guide hole furthest from said first connector, said rear face facing away from the first connector, so that a coupling direction of the female terminal is constrained in an extending direction of the male terminal when the guide hole introduces the guide rod so that a distal end of the male terminal contacts with a distal end of the female terminal, the guide hole extends through the second connector in the coupling direction thereof and the guide rod has a length longer than that of the guide hole in the coupling direction, so that the distal end of the guide rod extends through the second connector and projects beyond the rear facing face, and characterised in that said male hood surrounds a front portion of said female connector when said male and female connectors are fully interconnected, and in that said guide rod projects beyond said male hood so that when said male and female connectors are initially connected, said guide rod enters said guide hole before said male hood surrounds said female connector. The guide rod and guide means may be formed into circular or polygonal cross-sections. A plurality of guide rods and means may be provided in the male and female connectors in parallel to each other, respectively. In the connector assembly of the present invention, upon coupling of the female and male connectors, the projecting guide rod in one connector is fitted to the guide means in the other connector. At that time, the guide rod is introduced by the guide means, the coupling direction of the female terminal is constrained in the extending direction of the male terminal and both connectors are corrected so that they are completely opposed. When the distal end of the male terminal is to be inserted in the insertion port of the female housing, both connectors are constrained to be opposed in correct alignment. Thus, the male terminal is inserted in the coupling direction in the female housing without any partial contact of the male terminal. In addition, when the front face of the female connector engages with the distal end of the male hood of the male connector, the guide rod is introduced by the guide means to constrain the coupling direction. Consequently, even if both connectors are to be interconnected in their positions twisted with respect to the coupling direction, an opening edge of the male hood contacts with a front end face of the male connector. Thus, the end face of the female housing and to opening edge of the male hood are not deformed or broken. As described above, according to the present invention, when the distal end of the male terminal reaches the insertion port of the female housing, the coupling direction of the female terminal is constrained in the extending direction of the male terminal. Accordingly, it is possible to prevent the terminals from being worn due to the partial contact of the terminals and to enhance reliability of the connector assembly for a long period of time. In addition to the above effect, since the coupling directions of both connectors are restricted when the front end face of the female connector engages with the distal end of the male hood, it is possible to prevent the distal end of the male hood and the female housing from being broken. FIG. 1 is an exploded perspective view of a connector assembly of the present invention, illustrating female and male housings in a detached position; FIG. 2 is a partially broken-away front elevational view of a female connector in a connector assembly of the present invention; FIG. 3 is a longitudinal sectional view taken along lines III-III in FIG. 2; FIG. 4 is a central longitudinal sectional view of a female connector is a connector assembly of the present invention; FIG. 5 is a partially broken-away front elevational view of a male connector in a connector assembly of the present invention; FIG. 6 is a fragmentary longitudinal view taken along lines VI-VI in FIG. 5; FIG. 7 is an exploded longitudinal sectional view of a part of a connector assembly of the present invention, illustrating the male and female connectors in a position prior to fitting; FIG. 8 is a longitudinal sectional view of a part of a connector assembly of the present invention, illustrating hoods of the male and female connectors in their engaging positions; FIG. 9 is a longitudinal sectional view of a part of a connector assembly of the present invention, illustrating the male and female connectors in their coupling position; FIG. 10 is a perspective view of another embodiment of a male connector in a connector assembly of the present invention; FIG. 11 is a perspective view of still another embodiment of a male connector in a connector assembly of the present invention; FIG. 12 is a perspective view of still another embodiment of a male connector in a connector assembly of the present invention; and FIG. 13 is a longitudinal sectional view of a conventional connector assembly, illustrating the assembly in a failed coupling state. Referring now to FIGS. 1 through 9, embodiments of a connector assembly of the present invention, which are applied to a two pole waterproof connector assembly, will be explained below. As shown in FIG. 1, the connector assembly comprises a pair of female and male connectors. A male housing 1 of the male connector is provided with a rectangular box like male hood 10. A female housing 2 of the female connector is provided with a box like female hood 20 adapted to receive the male hood 10. When a lock projection 11 formed on an upper face of the male housing 1 engages with a lock shoulder 21a (see FIG. 3) formed in a distal end of an arm 21 on an upper portion of the female housing 2, the housings are locked with each other. As shown in FIGS. 2 and 3, the female housing 2 is provided on a central portion in a coupling direction with a boss 22 on which a retainer 27 described hereinafter is mounted. A waterproofing seal ring 23 is mounted on a proximal end of the boss 22. The male hood 10 is adapted to be fitted in a clearance between the boss 22 and the female hood 20 enclosing the boss 22. The boss 22 is provided on its center with a guide hole 24 extending through the female housing 2 and on opposite sides of the guide hole 24 with each female terminal accommodating chamber 25 adapted to receive a female terminal 4. As shown in FIG. 3, the chamber 25 is formed at a fitting side into a rectangular cross section suitable for receiving the female terminal and at the other side into a circular cross section suitable for receiving a rubber seal ring 5 through which an electrical wire W passes. The female terminal accommodating chamber 25 is provided on its middle lower portion with a tongue like lance 26 extending forwardly. The chamber 25 is provided below the lance 26 with a clearance S which allows a distal end of the lance 26 to be deflected up and down in the chamber 25. The lance 26 is provided on its upper end with projections 26a adapted to engage with opposite sides of the female terminal 4. Thus, when the female terminal 4 is inserted into the chamber 25 from a rear side of the female housing 2, the female terminal 4 advances in the chamber 25 while the distal end of the terminal 4 deflects the lance 26 downwardly. Then, when the female terminal 4 is completely inserted into the chamber 25, the projections 26a on the lance 26 engage with lock apertures (not shown) on opposite sides of the female terminal 4 to bring the female terminal 4 into a primary lock position. A retainer 27 is formed into a cap like body with a bottom wall and adapted to be mounted on the boss 22. The retainer 27 is fitted onto the boss 22 from its front side and locked on the boss 22 by pawls not shown. The retainer 27 is provided on its bottom wall with a bore corresponding to the guide hole 24. The retainer is also provided on its bottom wall with a tongue 27a which extends from the bottom wall into the clearance S to prevent the lance 26 from being deflected. Thus, when the retainer 27 is fitted onto the boss 22 from the front side, the tongue 27a enters the clearance S to prevent the lance 26 from being deflected downwardly, thereby bringing the female terminal 4 into a secondary lock position in which it is prevented from coming out of the chamber 25 by accident. The retainer 27 is also provided on its bottom wall in the axial direction of the chamber 25 with an insertion port 27b adapted to receive a female terminal 3. As shown in FIG. 4, the guide hole 24 is formed into a circular cross section adapted to introduce a guide rod 13 (described hereinafter) in the male housing 1. The center axis of the guide hole 24 is straight and coincides with the coupling directions of the female and male terminals 4 and 3. On the other hand, as shown in FIGS. 5 and 6, a male hood 10 projects from an outer periphery of a joining face 12 to a joining side and is provided on its distal end with a smooth end face 10a. The male hood 10 is provided on a center of the joining face 12 with the guide rod 13 which has a circular cross section suitable for entering the guide hole 24 in the female housing 2 and projects outwardly. The guide rod 13 has about two times the length from the joining face 12 to the end face 10a of the male hood 10. As shown in FIG. 8, when an end face 20a of the female hood 20 contacts with the end face 10a of the male hood 10, the guide rod 13 enters the guide hole 24 by more than half its depth. A waterproofing O-ring 15 is mounted in a groove 14 formed in a proximal end of the guide rod 13. Each male terminal 3 to be fitted to each female terminal 4 is disposed on the right and left sides on the joining face 12. The male terminal 3 is received in a terminal accommodating chamber (not shown) which is formed at the opposite side from the joining face 12 in the male housing 1 and has the same construction as that in the female housing 2. The male terminal 3 is brought into a secondary lock position by a retainer 16. A tab 3a at a free end of the male terminal 3 passes through a hole 17 (see FIG. 5) in the retainer 16 and projects in the male hood 10. When both housings 1 and 2 are coupled to each other so that the lock projection 11 on the upper portion of the male hood 10 engages with the lock shoulder 21a, the distal end face of the male hood 10 pushes the seal ring 23 and the distal end face of the guide hole 24 in the female housing 2 pushes the O-ring 15, thereby preventing water from entering interiors of both housings. Next, an operation of the above embodiment will be explained below. As shown in FIG. 7, in order to couple both connectors to each other, the distal end of the guide rod 13 is inserted into the guide hole 24, after the joining sides of both housings 1 and 2 are opposed in an axial direction. Even if the male housing 1 is inserted into the female housing 2 with the housing 1 being inclined with respect to housing 2, the guide rod 13 is introduced by the guide hole 24 while the inclination of the housings 1 and 2 is being corrected. As shown in FIG. 8, the inclination of the housings 1 and 2 is completely corrected and they are opposed to each other before the distal end face 20a of the female hood 20 of the female housing 2 engages with the distal end face 10a of the male hood 10 of the male housing 1. Thus, even if the male housing 1 is inserted into the female housing 2 with the housing 1 being twisted with respect to the housing 2, both distal end faces 10a and 20a contact with each other at four points. Consequently, even if they are strongly pressed with each other, they are prevented from being deformed or broken by the inclination of the housings 1 and 2. At a step of inserting the distal end of the male terminal 3 into the insertion port 27b, the guide rod 13 has already been introduced into the guide hole 24. Thus, as shown in FIG. 9, the male and female terminals 3 and 4 are coupled to each other with the coupling direction of the female terminal 4 being restrained in the extending direction of the male terminal 3 and the lock projection 11 engages with the lock shoulder 21a. It is possible to prevent the distal end of the male terminal 3 from partially contacting with the opening edge of the insertion port 27b or with the coupling aperture in the female terminal 4. Also, the male terminal 3 is not subject to deflection due to the partial contact. Accordingly, the male terminal 3 is not subject to local wear even if coupling and detaching of the connectors are repeated, thereby enhancing reliability of contact. In the case that the male and female housings 1 and 2 are detached from their coupled state, the engaging arm 21 is pushed down so that the lock pawl 21a on the arm 21 is inclined upwardly to release the lock projection 11. When the female housing 2 is drawn from the male housing 1, the guide rod 13 is guided by the guide hole 24 in the same manner as the inserting case of the female housing 2 and the female hood 20 is drawn from the male hood 10 in the coupling direction without causing an interference between them. In this embodiment, since the guide rod 13 is formed into a circular cross section, the guide rod 13 can be inserted through the guide hole 24, even if the male housing 1 is inserted into the female housing 2 with the housing 1 being twisted. Even if the coupling work cannot be visualized, it can be easily carried out. Although the above embodiment is applied to a connector assembly in which the male and female terminals 3 and 4 are received in the chambers in the male and female housings 1 and 2, it may be applied to a connector assembly in which each terminal is press-inserted in the housing. The present invention may have the following embodiments. (1) Although the guide rod 13 is formed into a circular cross section in the above embodiment, the guide rod 13 may be formed into a polygonal cross section such as a rectangular cross section (33) shown in FIG. 10, or a triangular cross section (43) shown in FIG. 11. If the guide rod 13 is inserted through the guide hole 24 in the embodiments shown in FIGS. 10 to 12, both housings are constrained in the twisting direction. The distal end faces of the male and female hoods do not strike each other, thereby causing no breakage of the hoods. Accordingly, it is sufficient to restrict only insertion direction when the distal end of the male terminal engages with the female housing and it is possible to shorten the guide rod. Further, it is possible to provide the guide rod on an exterior of the male housing not shown. This case can be applied to a multi-pole connector assembly, since the number of terminals to be coupled can be increased. (2) Although the above embodiment is applied to a waterproof connector assembly, the connector of the present invention should not be limited to it. (3) Although the guide rod 13 is inserted into the guide hole 24 to constrain the coupling direction in the above embodiment, the guide hole may be means for constraining the coupling direction of the guide rod such as rail-like guides.

Claims: A connector assembly comprising a male connector (1) having a projecting male terminal (3) and a male hood (10) around the male terminal coupled to a female connector (2) having a female terminal (4) to interconnect the male and female terminals, in which; a first one of said male and female connectors is provided with a guide rod (13) projecting in a coupling direction and having a distal end remote from said first connector, and a second one of the connectors is provided with a guide hole (24) for introducing the guide rod and a rear face at the end of said guide hole furthest from said first connector, said rear face facing away from the first connector, so that a coupling direction of the female terminal (4) is constrained in an extending direction of the male terminal (3) when the guide hole (24) introduces the guide rod (13) so that a distal end of the male terminal (3) contacts with a distal end of the female terminal (4), the guide hole extends through the second connector in the coupling direction thereof and the guide rod has a length longer than that of the guide hole in the coupling direction, so that the distal end of the guide rod (13) extends through the second connector and projects beyond the rear facing face, and characterised in that said male hood surrounds a front portion of said female connector when said male and female connectors are fully interconnected, and in that said guide rod (13) projects beyond said male hood so that when said male and female connectors are initially connected, said guide rod (13) enters said guide hole before said male hood surrounds said female connector. A connector assembly according to Claim 1 characterised in that said guide rod and hole (13, 24) are circular in cross section. A connector assembly according to Claim 1 characterised in that said guide rod and hole (13, 24) are polygonal in cross section. The connector assembly according to Claim 1 characterised in that said male hood (10) surrounds a front portion of said female connector.

Inventors: OKADA HAJIME, OKADA, HAJIME, OKADA, HAJIME, C/O SUMITOMO WIRING SYSTEMS, LTD.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEM, LTD.
Application year: 1994
Main classification: H01R13
IPC codes: H01R13